Definition:Truth Value/Aristotelian Logic

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In Aristotelian logic, a statement can be either true or false, and there is no undefined, in-between value.

Whether it is true or false is called its truth value.

Note that a statement's truth value may change depending on circumstances.

Thus, the statement:

It is currently raining on the grass outside my window

has the truth value false, whereas it had the truth value true last week.

The statement:

I am listening to Shostakovich's 4th symphony

is currently true, but that will last only for the next twenty minutes or so as I type.

The truth values true and false are usually represented in one of two ways:

$\T$ for true and $\F$ for false;
$1$ for true and $0$ for false.

There are advantages for both notations. In particular, the second lends itself to extending the discipline of logic into that of probability theory.

Also known as

The truth value of a statement can also be called its Boolean value, after George Boole.

Also see